It has been widely forecast that fabrication technology for computer chips will reach its limits in about a decade. The dramatic impact that this will have on almost every aspect of technological advance has motivated massive research efforts in industry, academia, and national laboratories to develop the replacement or extension strategy. The objective is to be able to make nanometer sized circuit elements, assemble them into complex circuits, integrate them with current semiconductor device technology, and maintain costs within acceptable limits. To this end, individual nanometer sized elements have been synthesized and shown to be electrically active. These include carbon nanotubes, oxide nanotubes, synthetic proteins and polypeptides, organic molecules, and the like. Present assembly proposals utilize chemical interactions and self-organization of molecules. Likewise, in optical fields the need for miniaturization requires the ability to fabricate optical devices having structures designed and built on the nanometer scale. The advantages afforded by such devices are already established theoretically, and it remains a challenge to create such devices with the beneficial properties predicted. A notable example of a pressing need for these materials is the data storage arena.
Metal nanostructures have been studied extensively in the field of nanoscience. Nanostructures' robust synthetic and functionalization chemistry, in combination with their interesting physical properties, make them ideal structures for fundamental research and applications. In particular, nanostructures made from noble metals, (e.g., Au and Ag) with their associated strong plasmon resonance have generated great interest. The fact that the plasmon response is a sensitive function of nanostructure geometry, coupled with synthetic advances that allow for controlled and systematic variations in nanostructure geometries, is leading to a dramatic increase in interest in this topic. This renaissance is also resulting in a new field called “plasmonics,” associated with the design and fabrication of nano-optical components that focus and manipulate light at spatial dimensions far below the classical diffraction limit. New applications of plasmonics, such as metal nanostructure-based strategies for chemical sensing, electromagnetic wave transport, and the development of new optically responsive materials have recently been reported. This is also stimulating an increased theoretical interest in the electronic and electromagnetic properties of nanoscale metal structures.
A formidable technical problem which remains unsolved is to devise a way to successfully position various different elements in a directed manner so as to produce devices, connect them to other components, such as electrodes, and integrate them into conventional as well as news systems (e.g., plasmonic systems). Important advances have been made using new lithographic techniques based on chemically controlled self assembly, microcontact printing, and self assembly in semiconductor film growth. Further advances are needed in preparing nanoscale electronic, opto-electronic and plasmonic devices which have not, heretofore, been made using ferroelectric nanolithography processes.